Background:

During the last years treatment aims in patients with rheumatoid arthritis (RA) have changed. Nowadays, achieving remission is a major goal. We therefore analyzed if the proportion of patients who achieved remission in DAS28 after several years of treatment with biologic agents changed during the last years.

Methods:

The analysis was based on RA patients enrolled in the German biologics register RABBIT at start of an anti-TNF treatment. Remission rates (DAS28 < 2.6) after three years of follow-up were compared between patients enrolled from 2001 to 2003 (n = 841) and those recruited from 2004 to 2006 (n = 1,290). Logistic regression was applied to compare both groups after adjustment for prognostic factors.

Results:

Crude remission rates at 36 months were significantly higher in patients enrolled between 20042006 than in those enrolled between 20012003 (26% vs. 19%). Higher rates were observed especially in patients with highly active disease (DAS28 > 6) at baseline (19.7% vs. 12.4 % in remission). The increase could not be explained by differences in baseline status.

The short term treatment response (DAS28 after 6 months) was the most distinct predictor for being in remission after 3 years. Additionally, male patients, younger patients, patients with better functional capacity and patients with a low disease activity at baseline had a higher chance of remission. When adjusting for these factors by multiple logistic regression the beneficial effect for patients enrolled between 20042006 was associated with the activity of the RA 6 months after start of treatment (Table).Patients with an active disease 6 months after start of treatment had a higher chance of remission when they were enrolled in the later period (table). This was not due to more treatment changes in patients registered later (37% vs. 37% patients who started another biologic) but was possibly caused by more frequent use of novel biologics with different mechanisms of action (14% vs. 3%).

Table 1. Probability of remission after 3 years estimated by multiple logistic regression stratified by enrollment period and level of disease activity after 6 months of the initial treatment.

DAS28 after 6 months

n

20012003 remission (%)

n

20042006 remission (%)

<= 3.2

217

40.3

427

38.5

> 3.2 & <= 4.1

180

19.6

308

25.4

> 4.1 & <= 5.1

200

11.0

271

18.8

> 5.1

244

3.6

284

10.0

total

841

18.3

1,290

25.0

Conclusion:

The availability of more treatment options accompanied with changes in treatment strategies increases the chance for RA patients to achieve remission.